rpmem_fip: return failure for a failed allocation

BZ: 

commit 14a76ef815d6bd22919b9c9351778ddc42d28212
Author: Jeff Moyer <jmoyer@redhat.com>
Date:   Thu Oct 19 17:21:35 2017 -0400

    rpmem_fip: return failure for a failed allocation
    
    rpmem_fip_getinfo will return 0 (success) when it fails to
    allocate space.  This can result in a NULL pointer dereference
    later on in callers.
    
    Signed-off-by: Jeff Moyer <jmoyer@redhat.com>

diff --git a/src/librpmem/rpmem_fip.c b/src/librpmem/rpmem_fip.c
index 87ffcaf..0993213 100644
--- a/src/librpmem/rpmem_fip.c
+++ b/src/librpmem/rpmem_fip.c
@@ -368,7 +368,7 @@ static int
 rpmem_fip_getinfo(struct rpmem_fip *fip, const char *node, const char *service,
 	enum rpmem_provider provider, enum rpmem_persist_method pm)
 {
-	int ret = 0;
+	int ret = -1;
 	struct fi_info *hints = rpmem_fip_get_hints(provider);
 	if (!hints) {
 		RPMEM_LOG(ERR, "!getting fabric interface information hints");